Process for producing a hydrocarbon component

ABSTRACT

The invention relates to a process for producing a new type of high-quality hydrocarbon base oil of biological origin. The process of the invention comprises ketonization, hydrodeoxygenation, and isomerization steps. Fatty acids and/or fatty acid esters based on a biological raw material are preferably used as the feedstock.

This Non-provisional Application is a Continuation of pendingapplication Ser. No. 12/433,394 filed on Apr. 30, 2009, which is aDivisional of pending application Ser. No. 11/636,567 filed on Dec. 11,2006, which claims priority under 35 U.S.C. §119(e) on U.S. ProvisionalApplication No. 60/749,036 filed on Dec. 12, 2005, the entire contentsof these applications are hereby incorporated by reference.

TECHNICAL FIELD

The invention relates to a process for producing a hydrocarboncomponent, and particularly a process for producing a high-qualitybranched saturated hydrocarbon component of biological origin to be usedas a new kind of base oil. The process comprising ketonisation,hydrodeoxygenation, and isomerization steps utilizes as feedstock rawmaterial of biological origin eventually derived from plant oils, animalfats, natural waxes, and carbohydrates. Also corresponding syntheticmaterials and combinations thereof may be used as feedstock.

STATE OF THE ART

Base oils are commonly used for the production of lubricants, such aslubricating oils for automotives, industrial lubricants and lubricatinggreases. They are also used as process oils, white oils and metalworking oils. Finished lubricants consist of two general components,lubricating base oil and additives. Lubricating base oil is the majorconstituent in these finished lubricants and contributes significantlyto the properties of the finished lubricant. In general, a fewlubricating base oils are used to manufacture a wide variety of finishedlubricants by varying the mixtures of individual lubricating base oilsand individual additives.

Base oils according to the classification of the American PetroleumInstitute (API) Group III or IV are used in high-quality lubricants. APIbase oil classification is shown in Table 1.

TABLE 1 API base oil classification Saturated Sulfur, wt-% Viscosityhydrocarbons, wt-% (ASTM D 1552/D 2622/ index (VI) Group (ASTM D 2007) D3120/D4294/D 4927) (ASTM D 2270) I <90 and/or >0.03 80 ≦ VI < 120 II ≧90≦0.03 80 ≦ VI < 120 III ≧90 ≦0.03 120 IV All polyalphaolefins (PAO) VAll other base oils not belonging to Groups I-IV

Oils of the Group III are base oils with very high viscosity indices(VHVI) produced by modern methods from crude oil by hydrocracking,followed by isomerization of the waxy linear paraffins to give branchedparaffins. Oils of Group III also include base oils produced from SlackWax paraffins from mineral oils, and from waxes obtained byFischer-Tropsch synthesis (GTL waxes) for instance from coal or naturalgas using corresponding isomerization techniques. Oils of Group IV aresynthetic polyalpha-olefins (PAO). A similar classification is also usedby ATIEL (Association Technique de l'Industrie Européenne desLubrifiants, or Technical Association of the European LubricantsIndustry), said classification also comprising Group VI:Polyinternalolefins (PIO). In addition to the official classification,also Group II+ is commonly used in this field, this group comprisingsaturated and non-sulfurous base oils having viscosity indices of morethan 110, but below 120. In these classifications saturated hydrocarbonsinclude paraffinic and naphthenic compounds, but not aromatics.

There is also available a definition for base stocks according to API1509 as: “A base stock is a lubricant component that is produced by asingle manufacturer to the same specifications (independent of feedsource or manufacturer's location); that meets the same manufacturer'sspecification; and that is identified by a unique formula, productidentification number, or both. Base stocks may be manufactured using avariety of different processes.” Base oil is the base stock or blend ofbase stocks used in API-licensed oil. The known base stock types are 1)Mineral oil (paraffinic, naphthenic, aromatic), 2) Synthetic(polyalphaolefins, alkylated aromatics, diesters, polyol esters,polyalkylene glycols, phosphate esters, silicones), and 3) Plant oil.

Already for a long time, especially the automotive industry has requiredlubricants and thus base oils with improved technical properties.Increasingly, the specifications for finished lubricants requireproducts with excellent low temperature properties, high oxidationstability and low volatility. Generally lubricating base oils are baseoils having kinematic viscosity of about 3 cSt or greater at 100° C.(KV100); a pour point (PP) of about −12° C. or less; and a viscosityindex (VI) about 120 or greater. In addition to low pour points also thelow-temperature fluidity of multi-grade engine oils is needed toguarantee that in cold weather the engine starts easily. Thelow-temperature fluidity is demonstrated as apparent viscosity in coldcranking simulator (CCS) tests at −5 to −40° C. temperature. Lubricatingbase oils having KV100 of about 4 cSt should typically have CCSviscosity at −30° C. (CCS-30) lower than 1800 cP and oils having KV100of about 5 cSt should have CCS-30 lower than 2700 cP. The lower thevalue is the better. In general, lubricating base oils should have Noackvolatility no greater than current conventional Group I or Group IIlight neutral oils. Currently, only a small fraction of the base oilsmanufactured today can be used in formulations to meet the latest, mostdemanding lubricant specifications.

It is no longer possible to produce lubricants complying with thespecifications of the most demanding car manufacturers, fromconventional mineral oils. Typically, mineral oils often contain toohigh concentrations of aromatic, sulfur, and nitrogen compounds, andfurther, they also have a high volatility and a modest viscosity index,that is, viscosity-temperature dependence. Moreover, response of mineraloils to antioxidant additives is often low. Synthetic and so-calledsemi-synthetic base oils play an increasingly important role especiallyin automotive lubricants, such as in engine and gear oils. A similardevelopment can be seen for industrial lubricants. Service life oflubricants is desirably as long as possible, thus avoiding frequent oilchanges by the user, and further allowing extended maintenance intervalsof vehicles for instance in commercial transportation. In the pastdecade, engine oil change intervals for passenger cars have increasedfive fold, being at best 50,000 km. For heavy-duty vehicles, engine oilchange intervals are at present already on the level of 100,000 km.

The production of lubricants is influenced by increasingly common “LifeCycle Approach” (LCA) concerning environment, health and safety factorsof the product. What is aimed with LCA are an extended service life ofthe product, and minimal drawbacks to the environments associated withthe production, use, handling and disposal of the product. Longer oilchange intervals of high-quality base oils result in decreasedconsumption of non-renewable mineral crude oil based raw materials, andlower amounts of hazardous waste oil products.

In addition to the demands for engine technology and base oilproduction, also strict environmental requirements direct the industryto develop more sophisticated base oils. Sulfur free fuels and base oilsare required in order to gain full effect of new and efficientanti-pollution technologies in modern vehicles and to cut emissions ofnitrogen oxides, volatile hydrocarbons and particles, as well as toachieve direct reduction of sulfur dioxide in exhaust gases. TheEuropean Union has decided that these fuels shall be available to themarket from 2005 and they must be the only form on sale from 2009.Conventional mineral oil base oils contain sulfur, nitrogen, aromaticcompounds, and typically also volatile compounds. They are less suitablefor new engines and thus also environmentally more detrimental thannewer sulfur and aromatic free base oils.

Nowadays, the use of recycled oils and renewable raw materials in theproduction of lubricants is frequently an object of interest. The use ofrenewable raw materials of biological origin instead of non-renewablefossil raw materials to produce hydrocarbon components is desirable,because the fossil raw materials are exhaustible and their effect onenvironment is detrimental. Problems associated with recycled oilsinclude complicated purification and reprocessing steps to obtain baseoils with high quality. Further, the development of a functioning andextensive recycling logistic system is expensive.

For the time being, only esters are used in lubricants of renewable andbiological origin. The use of said esters is limited to a few specialapplications such as oils for refrigeration compressor lubricants,bio-hydraulic oils and metal working oils. In normal automotive andindustrial lubricants, they are used mainly in additive scale. Highprice also limits the use of esters. In addition, the esters used inengine oil formulations are not interchangeable with other esterswithout performing new engine tests, even in cases where the chemicalcomposition of the substituting ester is in principle similar. Instead,base oils consisting of pure hydrocarbon structure are partlyinterchangeable with each other. There are also some technical problemsassociated with esters. As polar compounds, esters suffer greaterseal-swelling tendency than pure hydrocarbons. This has created lot ofproblems relating to elastomer in hydraulic applications. In addition,ester base oils are hydrolyzed more easily producing acids, which inturn cause corrosion on lubricating systems. Further, even greaterdisadvantage of esters is that additives developed for non-polarhydrocarbon base oils are not effective for ester base oils.

Ketones are commonly used as antifoam agents, mould release agents, andin mixtures with paraffin as metal coatings, as well as components ofprinting inks. Processes for producing ketones are known in the art,where the functional groups of the feed molecules react with each otherforming a ketone. The carbon number of the ketone formed is reduced byone compared to the sum of the carbon numbers of the reacted feedmolecules. Metals or oxides of alkaline earth metals are used ascatalysts. EP 591297 describes a method for producing a ketone fromfatty acids by pyrolysis reaction using a magnesium oxide catalyst. EP0457665 discloses a method for producing ketones from triglycerides,fatty acids, fatty acid esters, fatty acid salts, and fatty acidanhydrides using a bauxite catalyst containing iron oxide.

Ketones may be reduced to paraffins using Wolff-Kishner reduction. Thereaction involves converting a ketone to the corresponding hydrazone(H₂NNH₂) and decomposition of this intermediate in the presence of baseat about 200° C. to yield the reduced alkyl derivative and nitrogen.Ketone is normally heated with hydrazine hydrate and sodium hydroxide at100-200° C. temperature. Diethylene glycol or dimethyl sulfoxide is usedas solvent. Alternatively, direct reduction of the carbonyl group togive a methylene group may be carried out with Clemmensen reductionreaction catalyzed by amalgam zinc and hydrochloric acid. Also a methodfor reducing ketones by catalytic hydrogenation with palladium on carboncatalyst at 50-150° C. temperature, under a hydrogen pressure between0.1 and 0.5 MPa is known. With non-noble metals such as nickel, a highertemperature of nearly 200° C., and a hydrogen pressure of 30 MPa must beused as disclosed in Ullmanns Encyclopädie der technischen Chemie, 4.neubearbeitete and erweiterte Auflage, Band 13, Verlag Chemie GmbH,Weinheim 1983, Hydrierung p. 140.

FI 100248 presents a process with two steps wherein middle distillate isproduced from plant oil by hydrogenation of the carboxylic acids ortriglycerides of said plant oil to yield linear normal paraffins,followed by isomerization of said n-paraffins to give branchedparaffins. The hydrogenation was performed at a temperature ranging from330 to 450° C., under a pressure of higher than 3 MPa and liquid hourlyspace velocity (LHSV) being from 0.5 to 5 l/h. The isomerization stepwas carried out at 200 to 500° C. temperature, under elevated pressure,and LHSV being from 0.1 to 10 l/h.

EP 774451 discloses a process for isomerization of fatty acids or fattyacid alkyl esters. The isomerization of unsaturated fatty acids or fattyacid alkyl esters is performed using clay or another cationic catalyst.In addition to the main product, also feedstock dimers are obtained.After distillation, unsaturated branched fatty acids or fatty acid alkylesters are obtained as the product.

GB 1 524 781 discloses a process for producing hydrocarbons from plantoil. In this process, the plant oil feed is pyrolyzed in three zones inthe presence of a catalyst at temperature of 300-700° C. In the processhydrocarbons of the gas, gasoline, and diesel classes are obtained. Theyare separated and purified.

Starting materials originating from biological sources contain highamounts of oxygen. In processing oxygen is converted to water, carbonmonoxide, and carbon dioxide. In addition, starting materials ofbiological origin often contain nitrogen, sulfur and phosphorus known ascatalyst poisons and inhibitors of noble metal catalysts. They causedecreased service life of the catalyst, and make frequent regenerationof the catalysts necessary. Noble metal catalysts are used inisomerization processes. They are very expensive and highly sensitive tocatalyst poisons.

Typical basic structural unit of plant and fish oils and animal fats isa triglyceride. Triglyceride is an ester of glycerol with three fattyacid molecules having the structure below:

wherein R₁, R₂ and R₃ represent C4-C26 hydrocarbon chains. The length ofthe hydrocarbon chain is mainly 18 carbons (C18). C18 fatty acids aretypically bonded to the middle hydroxyl group of glycerol. Typicalcarbon numbers of the fatty acids linked to the two other hydroxylgroups are even, being generally between carbon numbers C14 and C22.

Prior to processing, starting materials of biological origin arecommonly pretreated with suitable known methods such as thermally,mechanically for instance by means of shear force, chemically forinstance with acids or bases, or physically with radiation,distillation, cooling, or filtering. The purpose of chemical andphysical pretreatments is to remove impurities interfering with theprocess or poisoning the catalysts, and reduce unwanted side reactions.

The pretreated biological raw material is often also preprocessed usinga known method such as hydrolysis, transesterification, reduction, orsaponification. Fatty acids may be produced from triglycerides bythermal pyrolysis treatment. In a hydrolysis reaction, oils and fatsreact with water yielding free fatty acids and glycerol as the product.Three main processes for the industrial production of fatty acids areknown: Vapor splitting of triglycerides under high pressure, basichydrolysis, and enzymatic hydrolysis. In the vapor splitting process,the hydrolysis of triglycerides using steam is carried out attemperatures between 100 and 300° C., under a pressure of 1-10 MPa,preferable conditions being from 250 to 260° C. and from 4 to 5.5 MPa.Metal oxides like zinc oxide may be added as the catalyst to acceleratethe reaction. High temperature and pressure contribute to thedissolution of fats in water.

Fatty acid esters like triglycerides may be transesterified with analcohol to obtain fatty acid alkyl esters. In the transesterificationreaction the triglyceride structure is decomposed, the carboxylic acidyielding an ester with the alcohol, whereas the glycerol moiety of thetriglyceride is liberated. Typically, methanol is used as the alcohol,but also other C1-C11 alcohols may be used. Sodium and potassiumhydroxides dissolved in excess in methanol are used as catalysts.Typical conditions for the transesterification are as follows:Temperature between 60 and 70° C., pressure between 0.1 and 2 MPa.Esterification of free carboxylic acids with alcohol requires highertemperature and pressure (e.g. 240° C. and 9 MPa), or acidic conditions.For this reason, any free fatty acids present in the transesterificationfeed should be removed. Alternatively they can be separately esterifiedfor instance using a sulfuric acid catalyst either before or aftertransesterification.

Acidic groups of fatty acids may be directly reduced to alcohols withlithium aluminium hydride, the double bonds thus remaining in alcohols,or in a manner used in industrial scale by hydrogenation of the fattyacid alkyl esters produced by transesterification to saturated alcohols.In the hydrogenation reaction, the alcohol moiety used for thetransesterification is liberated and may be recycled. Fatty acid alkylesters are reduced with metal catalysts, typically with copper chromiteunder a hydrogen pressure between 25 and 30 MPa, at 210° C. The C1-C3alcohol liberated in the reaction is separated from the heavier fattyalcohol. Also chromium, iron or preferably rhodium activated nickelcatalysts may be used at a temperature between 200 and 230° C. and undera hydrogen pressure of 25 MPa. Unsaturated alcohols are obtained in casea copper-zinc catalyst is used.

Fatty aldehydes may be produced from fatty alcohols by removing hydrogenin a dehydrogenation reaction. The reaction is opposite to thehydrogenation reaction of alcohols, and thus endothermic. In thedehydrogenation reaction corresponding hydrogenation catalysts are usedbut the temperature is higher, and thus side reactions such as cracking,isomerization, cyclization, and polymerization are possible. Supportedcopper chromite catalysts are typically used for producing aldehydesfrom alcohols. In gas phase dehydrogenation, typically a temperaturebetween 250 and 400° C., and a pressure between 0.1 and 0.5 MPa areused. Moreover, it is generally known that corresponding aldehydes canbe produced from alcohols using alumina, silica-alumina, hafnium oxideand zirconium oxide as catalyst. The products of the process arecontrolled by changes in process temperature. At low temperatures ethersare obtained, high temperatures give aldehydes, whereas olefins aretypically obtained at 300-350° C.

Oils, fats and free fatty acids may be saponified in aqueous solutionsby reaction with metal hydroxides such as alkali metal hydroxidesyielding metal salts of fatty acids, and glycerol. In addition to sodiumhydroxide, also for instance potassium oxide or zinc oxide may be used.In this case the formed soap has poor solubility in water and is readilyisolated from the glycerol, which is soluble in water. In a traditionalsaponification process, the basic hydrolysis of triglycerides isperformed at about 100° C., under normal pressure.

Neither the use of heteroatom containing starting materials ofbiological origin in a process for producing high-quality saturated baseoils has not been disclosed, nor there are any reports about the use ofheteroatom containing, optionally thermally and/or chemically and/orphysically and/or mechanically treated intermediate materials ofbiological origin in a process for producing high-quality saturated baseoils.

On the basis of the above teaching it may be seen that there is anobvious need for an alternative process for producing branched saturatedhydrocarbon components from starting materials of biological origin.There is also a need for nonpolar saturated base oils complying with thequality requirements for high-quality base oils, said base oils beingpreferably of biological origin and having more preferable effects onthe environment and for end users than traditional mineral base oils.

OBJECT OF THE INVENTION

An object of the invention is a process for producing a hydrocarboncomponent.

A further object of the invention is a process for producing ahydrocarbon component using starting materials of biological origin.

Another object of the invention is a process for producing a new type ofbase oil.

Still another object of the invention is a process for producing adiesel component.

Further, another object of the invention is a process for producing agasoline component.

Another object of the invention is a process for producing saturatedbase oil and diesel component from starting materials of biologicalorigin, said products mainly not containing heteroatoms.

An object of the invention is moreover a base oil complying with therequirements of the API Group III.

The characteristic features of the process and base oils of theinvention are presented in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a preferred embodiment of theinvention for a process wherein the ketonisation is carried out prior tohydrodeoxygenation and isomerization.

FIG. 2 is a schematic representation of a preferred embodiment of theinvention for a process wherein fatty acids are isomerized prior to theketonisation and hydrodeoxygenation steps.

FIG. 3 is a graph showing the carbon number distributions of VHVI(413-520° C. cut) and the baseoils of invention (360° C. cut).

GENERAL DESCRIPTION OF THE INVENTION

The process of the invention for producing a hydrocarbon component, andparticularly a high-quality saturated hydrocarbon base oil of biologicalorigin, comprises a ketonisation step, a hydrodeoxygenation step and anisomerization step. The isomerization step refers here both toisomerization of unsaturated carboxylic acids and alkyl esters ofcarboxylic acids, particularly unsaturated fatty acids and fatty acidalkyl esters, and also isomerization of paraffins. Isomerization offatty acids and fatty acid alkyl esters is performed prior to theketonisation step, whereas the isomerization of paraffins is carried outfollowing the ketonisation and HDO steps.

Carboxylic acids and their derivatives or combinations thereof,preferably fatty acids, fatty acid esters, fatty alcohols, fattyaldehydes, anhydrides of fatty acids, or metal salts of fatty acids ofbiological origin, are used as the feedstock of the process. Saidstarting materials of biological origin may be pretreated if necessary,and/or preprocessed using known methods.

Here, saturated base oil comprises saturated hydrocarbons. The term“saturated hydrocarbons” refers to paraffinic and naphthenic compounds,but not to aromatics. Paraffinic compounds may either be branched orlinear. Naphthenic compounds are cyclic saturated hydrocarbons, orcycloparaffins, typically derived from cyclopentane or cyclohexane. Anaphthenic compound may comprise a single ring structure (mononaphthene)or two isolated ring structures (isolated dinaphthene), or two fusedring structures (fused dinaphthene) or three or more fused ringstructures (polycyclic naphthenes or polynaphthenes).

Here, ketonisation refers to the ketonisation reaction of carboxylicacids and the derivatives thereof, particularly fatty acids,corresponding esters, alcohols, aldehydes, anhydrides, and metal salts.In the reaction the functional groups of the feedstock react with eachother yielding ketones. The ketonisation reaction of two carboxylicacids proceeds through an anhydride intermediate to give a ketone, waterand carbon dioxide liberating in the reaction. In the pyrolyticketonisation reaction of anhydrides and metal salts carbon dioxide isliberated. For alcohols and esters, the ketonisation reaction proceedsvia aldehydes to give a Tishchenko ester and further to ketones, foraldehydes via Tishchenko esters to ketones. In these two last reactionscarbon monoxide and hydrogen is liberated.

Fatty acids refer here to carboxylic acids of biological origin, havingcarbon numbers higher than C1.

Fatty acid esters refer here to triglycerides, fatty acid alkyl esters,esters of fatty acids with fatty alcohols, and natural waxes, all beingof biological origin.

In this context, the term polyol refers to alcohols having two or morehydroxyl groups.

Here, hydrodeoxygenation (HDO) refers to oxygen removal from a compoundby means of hydrogen. Water is liberated in the reaction, andsimultaneously olefinic double bonds are hydrogenated and any sulfur andnitrogen compounds are removed. Reactions of the HDO step areexothermal. After the HDO step, the structure of the starting materialhas become paraffinic.

In this context, isomerization refers both to the isomerization ofcarboxylic acids and alkyl esters thereof, and to hydroisomerization.

Isomerization of unsaturated carboxylic acids or alkyl esters ofcarboxylic acids, particularly fatty acids or fatty acid alkyl estersrefers here to their conversion to branched compounds without alteringtheir carbon number.

Hydroisomerization refers here to the isomerization of linear paraffinsto give branched paraffins.

In this context, carbon number range refers to the difference of thecarbon numbers of the largest and the smallest molecules, plus one, inthe final product.

In this context, pressures are gauge pressures relative to normalatmospheric pressure.

Classification of the Periodic System of the Elements is the IUPACclassification.

The invention is now illustrated with the appended FIGS. 1 and 2 withoutwishing to limit the scope of the invention to the embodiments of saidfigures.

FIGURES

FIG. 1 shows schematically a preferable embodiment of the invention fora process wherein the ketonisation is carried out prior tohydrodeoxygenation and isomerization.

FIG. 2 shows schematically another preferable embodiment of theinvention for a process wherein fatty acids are isomerized prior to theketonisation and hydrodeoxygenation steps.

In FIG. 1, at least one of the following starting materials isintroduced to the feed tank 30 either as separate components or asmixtures: fatty acids 4, fatty acid esters 9, aldehydes 5, alcohols 6 oracid anhydrides 7, and dicarboxylic acid feed 3 or polyols 13 isintroduced as optional additional feedstock. Part of the lighterrecirculated product fraction (for instance 102) or another hydrocarbonstream 201 may be optionally added to the feed tank 30 as a diluent. Thediluent stream 202 comprises the recirculated stream 102 or hydrocarbonstream 201 or a mixture thereof. From the feed tank 30, the feedstockstream 31 and hydrogen stream 105 are passed to an optionalprehydrogenation reactor 40, followed by the passing of theprehydrogenated stream 41 to the ketonisation reactor 50, optionallyalso receiving the diluent 202. From the ketonization reactor 50, theketone product 51 and hydrogen stream 105 are passed to thehydrodeoxygenation reactor 60, optionally also receiving the diluent202. The paraffinic product 61 from the hydrodeoxygenation reactor 60 ispassed to stripping 70 where unwanted impurities are removed.Thereafter, the paraffinic product stream 71 and hydrogen stream 105 arepassed to hydroisomerization reactor 80, optionally also receivingadditional paraffinic feedstocks such as slack wax and Fisher-Tropschwaxes or waxes produced by gasification of biomaterial (biomaterial toliquids, BTL) 8, and the diluent 202. Following hydroisomerization 80,branched paraffins 81 may be subjected to optional hydrofinishing 90using a hydrogen stream 105, followed by passing the product as thestream 91 to a distillation and separation unit 100. Branched paraffins82 may optionally be passed from the hydroisomerization reactor 80 todewaxing 110 wherein linear paraffins are removed either with solventsor catalytically in a known manner. Separated linear paraffins may berecirculated as stream 111 to the hydroisomerization reactor 80 forparaffins, while branched paraffins are passed as the stream 112 to thehydrofinishing reactor 90. In the distillation and/or separation unit110, product components boiling at different temperature ranges and/orfor special applications; gasses 104, gasoline 101, diesel 102, and baseoil 103, are separated.

In FIG. 2, the unsaturated free fatty acid 3 and fatty acid alkyl esterfeed 21 are introduced into the feed tank 30 as separate components oras mixtures. Part of the lighter product fraction to be recirculated(for instance 102) or another hydrocarbon 201 may be optionally passedto the feed tank 30 as a diluent. The diluent stream 202 comprises therecirculated stream 102 or hydrocarbon stream 201 or a mixture thereof.From the feed tank 30, the feedstock stream 31 containing fatty acidsand/or fatty acid alkyl esters is passed to the isomerization reactor 40for branching the components. Following isomerization, but prior toketonisation, an optional prehydrogenation may be performed whereinbranched fatty acid and/or fatty acids alkyl ester components are passedas the stream 41 to the double-bond prehydrogenation reactor 50 alsoreceiving the hydrogen stream 6 and the optional diluent 202. Thereafterthe fully saturated branched fatty acid and/or fatty acid alkyl esterfeedstock 51 is introduced to the ketonization reactor 60 optionallyalso receiving the dicarboxylic acid feed 5, and the optional diluent202. Following ketonization 60, the ketone product 61 and hydrogenstream 6 are passed to hydrodeoxygenation reactor 70 optionally alsoreceiving the diluent 202. Following hydrodeoxygenation 70, the branchedparaffinic product stream 71 and hydrogen stream 6 may be optionallypassed to hydrofinishing 80. From the hydrofinishing reactor 80, thebranched paraffinic product obtained is passed as the stream 81 to adistillation and separation unit 90 wherein product components boilingat different temperature ranges and/or for special applications; gas100, diesel 102, and base oil 103, are separated.

DETAILED DESCRIPTION OF THE INVENTION

It was now surprisingly found that branched saturated hydrocarboncomponents, suitable as high-quality base oils, not containingheteroatoms may be obtained by the process of the invention. Feedselected from carboxylic acids and/or derivatives thereof, preferablyfatty acids, esters of fatty acids, fatty alcohols, fatty aldehydes,anhydrides of fatty acids, and metal salts of fatty acids of biologicalor synthetic origin, or combinations thereof may be used in the process.In the process of the invention, ketonisation, hydrogenation, andisomerization reactions are utilized. Branched saturated hydrocarboncomponents are obtained as the product.

In the ketonisation reaction the length of the hydrocarbon chain of thefeedstock is increased to such that only carbon-carbon bonds are left inthe basic structure of the molecule. Such a ketone is not suitable asbase oil. The oxygen present in the ketone group must be removed, andthe low temperature properties must be improved for instance by makingshort branches to the molecular structure.

In the process of the invention, the feedstock is subjected toketonisation, hydrodeoxygenation, and isomerization. In case unsaturatedcarboxylic acids and/or esters of unsaturated carboxylic acids,preferably fatty acids and/or fatty acid alkyl esters are used as thefeedstock, the isomerization may be performed prior to ketonisationfollowed by hydrodeoxygenation, otherwise the isomerization is carriedout after ketonization and hydrodeoxygenation steps.

Feed selected from the group consisting of carboxylic acids andderivatives thereof, preferably fatty acids, esters of fatty acids,fatty alcohols, fatty aldehydes, anhydrides of fatty acids, or metalsalts of fatty acids, of biological origin, or combinations thereof isketonised in the process. By this means the hydrocarbon chain length ofthe feedstock may be increased, and it preferably reaches the carbonnumber of the base oil. In the ketonisation step one may also utilizefeedstocks that are different than those based on fatty acids. Suchcomponents are for example dicarboxylic acids or polyols. Thesefeedstocks are ketonised at all the functional groups, thus increasingthe molecular mass of the product compared to ketones formed of only twofatty acids. In this case, a polyketone molecule is formed, saidpolyketone being treated in a similar manner as monoketones. Ifnecessary, the biological starting material may be subjected to one ormore pretreatment or purification steps of the prior art for preparationof the feedstock before ketonisation reaction.

In the hydrodeoxygenation step of the process of the invention, theketone is treated with hydrogen to give paraffins. The oxygen present inthe ketone is liberated as water, and any other oxygen, nitrogen, andsulfur containing compounds are hydrogenated to paraffins, too. Inaddition, olefinic bonds are hydrogenated. After hydrodeoxygenationlight hydrocarbons are removed as gases.

The hydrocarbon component obtained from the hydrodeoxygenation step maybe subjected to hydroisomerization giving branched hydrocarbon chains.Following hydroisomerization step, the oxidation stability of theproduct may be improved using an optional finishing treatment. Inaddition, an optional dewaxing may be performed prior to or after thefinishing.

In case unsaturated carboxylic acids or esters such as fatty acidsand/or fatty acid alkyl esters are used as the feedstock, theisomerization may be carried out prior to ketonization, followed then byketonization of the isomerized product, and the HDO step is performed asthe last step of the process. In said isomerization, branches are formedin the structure of the compound, thus giving a mixture of isomerizedcomponents. Dimers, and to a lesser extent trimers of the feedstockcomponents are obtained as by-products.

The steps of the process of the invention are preferably carried out inthe order of ketonisation, hydrodeoxygenation, and as the last stepisomerization.

The process may also be used for processing of mixtures feedsoriginating from biological starting materials and synthetic feedstocks,in which case additional synthetic feedstocks, or feedstocks producedwith other processes may be used. Also pure synthetic feedstocks may beused, but then the products are not based on renewable naturalresources. In the processing, in addition to paraffins of biologicalorigin such as paraffins obtained in the process of invention or BTLparaffins produced in processes of biomaterial gasification, alsoFischer-Tropsch waxes and/or Slack waxes obtained from crude oil bysolvent dewaxing may be used as additional feedstocks inhydroisomerization. Of synthetic processes, the oxo-process andFischer-Tropsch synthesis are stages in known processes for producingliquid products from starting materials containing carbon and hydrogen,such as from coal or natural gas.

Feedstock

The feed comprises at least one component selected from triglycerides,carboxylic acids having a carbon number C1-C38, esters of C1-C38carboxylic acids with C1-C11 alcohols, C1-C38 alcohols, C1-C38aldehydes, C1-C38 carboxylic acid anhydrides, and metal salts of C1-C38carboxylic acids. Preferable feedstocks are C4-C24 fatty acids ofbiological origin, and/or the derivatives thereof, mentioned above, orcombinations thereof. Preferable components of the feedstock are C4-C24fatty acids, C4-C24 fatty acid alkyl esters such as methyl esters, andesters of fatty acids with C12-C38 alcohols having long chains, naturalwaxes, C4-C24 fatty alcohols reduced from fatty acids, C4-C24 aldehydesreduced from fatty acids, C4-C24 fatty acid anhydrides, and metal saltsof C4-C24 fatty acids. Dicarboxylic acids, polyols, triglycerides, andtheir mixtures with the above mentioned feedstocks may also be used asfeed components.

Feed components are produced using any known methods, preferably fromstarting materials of biological origin, such as materials derived fromplants, animals and fishes, selected from the group consisting of plantoils, plant waxes, plant fats, animal oils, animal fats, animal waxes,fish oils, fish fats, fish waxes. Corresponding starting materialsderived from algae and insects are also contemplated as well as startingmaterials derived from aldehydes and ketones prepared fromcarbohydrates. C1-C38 and preferably C4-C24 fatty acids, orcorresponding hydroxy acids or alcohols, act as structural units insuitable starting materials of biological origin. Since in theprocessing of fatty acids the service life of the catalyst is typicallyshort, esters and alcohols may be optionally used as feedstocks causingless coke formation on the catalyst.

The starting materials of biological origin are suitably selected fromthe group consisting of:

-   a) plant fats, plant oils, plant waxes, animal fats, animal oils,    animal waxes, fish fats, fish oils, fish waxes, and-   b) free fatty acids or fatty acids obtained by hydrolysis, acid    transesterification or pyrolysis reactions from plant fats, plant    oils, plant waxes, animal fats, animal oils, animal waxes, fish    fats, fish oils, fish waxes, and-   c) esters obtained by transesterification from plant fats, plant    oils, plant waxes, animal fats, animal oils, animal waxes, fish    fats, fish oils, fish waxes, and-   d) fatty acid alkyl esters obtained by esterification of alcohols    with fatty acids of plant, animal and fish origin, and-   e) fatty acid metal salts obtained by saponification of free fatty    acids, plant fats, plant oils, plant waxes, animal fats, animal    oils, animal waxes, fish fats, fish oils, fish waxes, and-   f) alcohols and aldehydes obtained as reduction or hydrogenolysis    products of free fatty acids, or fatty acids from plant fats, plant    oils, plant waxes, animal fats, animal oils, animal waxes, fish    fats, fish oils, fish waxes, and-   g) fatty alcohols obtained by hydrolysis, transesterification and    pyrolysis from waxes of biological origin, and-   h) anhydrides of fatty acids from plant fats, plant oils, plant    waxes, animal fats, animal oils, animal waxes, fish fats, fish oils,    fish waxes, and-   i) waste and recycled food grade fats and oils, and fats, oils and    waxes obtained by genetic engineering, and-   j) mixtures of said starting materials.

Metal salts are alkaline earth or alkali metal salts, preferably Ca, Zn,Mg, Al, or Na salts. Natural waxes are fatty acids esterified withalcohols having long hydrocarbon chains. The carbon number of fatty acidand alcohol hydrocarbon chains is typically from C12 to C38.

The starting material of biological origin may also be other thantriglyceride, ester, fatty acid, alcohol or aldehyde, or a mixture ofthe said starting materials if the hydrocarbon chain length of thebiological starting material is suitable or can be processed to besuitable to the level required for diesel and base oil applications.

If necessary, the starting material of biological origin may bepretreated or purified by suitable known methods as described above. Forinstance it may be distillated to fractions having narrower boilingranges or carbon number distributions or ranges. Furthermore theimpurities detrimental to the properties of the feedstock or finalproduct may be removed by filtration through suitable filtering aids.

In addition to compound types described above, also totally or partlysynthetic compounds, as well as mixtures of the compound types describedabove with synthetic compounds are also suitable feedstocks.

Examples of suitable biological starting materials include fish oilssuch as baltic herring oil, salmon oil, herring oil, tuna oil, anchovyoil, sardine oil, and mackerel oil; plant oils such as rapeseed oil,colza oil, canola oil, tall oil, sunflower seed oil, soybean oil, cornoil, hemp oil, olive oil, cottonseed oil, mustard oil, palm oil, peanutoil, castor oil, jatropha seed oil, palm kernel oil, and coconut oil;and moreover, suitable are also animal fats such as lard, tallow, andalso waste and recycled food grade fats and oils, as well as fats, waxesand oils produced by genetic engineering. In addition to fats and oils,suitable starting materials of biological origin include animal waxessuch as bee wax, Chinese wax (insect wax), shellac wax, and lanoline(wool wax), as well as plant waxes such as carnauba palm wax, ouricouripalm wax, jojoba seed oil, candelilla wax, esparto wax, Japan wax, andrice bran oil.

In the ketonization step of the process of the invention, also freecarboxylic acids or esters thereof may optionally be used as feedstocks.These linear or branched mono and/or dicarboxylic acids may be producedby petrochemical processes or oxo processes. Suitable monocarboxylicacids include for instance propionic, butyric, isobutyric, 2-methylbutanoic, 2-ethyl butanoic, valeric, isovaleric, caproic, heptanoic,caprylic, pelargonic, isononanoic, caprinic, lauric, myristic,myristoleic, palmitic, palmitoleic, stearic, oleic, elaidic, linolic,linoleic, arachidonic, behenic, and lignin acids. Suitable dibarboxylicacids include for example the following: oxalic, malonic, succinic,glutaric, adipic, pimelic, suberic, azelaic, and sebasic acids.

In case where alcohols are ketonised in the process of the invention,also diols and/or polyols may be used as the feedstock in addition tofatty alcohols. Suitable diols include for instance diols derived fromdicarboxylic acids, dimers of fatty alcohols, and2,2-dimethyl-1,3-propanediol (NPG). Examples of suitable polyhydricalcohols include glycerol, 2-ethyl-2-hydroxymethyl-propane-1,3-diol(TMP), 2-methyl-2-hydroxymethyl-propane-1,3-diol (TME),2-butyl-2-ethyl-propanediol (BEPD), and2,2-bis-(hydroxymethyl)-1,3-propanediol (PET). Preferably alcoholscontaining tertiary carbons are not used when the thermal stability ofthe base oil to be produced has to be good.

Feedstocks used in the isomerization of unsaturated carboxylic acids, oralkyl esters of unsaturated carboxylic acids; particularly in theisomerization of unsaturated fatty acids or fatty acid esters, containat least 20%, preferably at least 50%, and particularly preferably atleast 80% by weight of compounds having double bonds. The feedstock mayalso be a mixture of unsaturated carboxylic acids and unsaturatedcarboxylic acid alkyl esters. Typically, the number of unsaturated bondsin compounds of the feedstock is 1 to 3. Preferably the feedstockcomprises at least 40% by weight of monounsaturated fatty acids or fattyacid esters, more preferably at least 70% by weight. The feedstock mayalso comprise polyunsaturated fatty acids or fatty acid esters. Thepresence of an unsaturated bond in the molecule causes the formation ofa cation as an intermediate, thereby facilitating the skeletalisomerization reaction.

Hydrocarbon may optionally be added as a diluent to the feedstock and/orin various process stages, such diluent may be for instance hydrocarbonof the middle distillate diesel class. Boiling ranges of hydrocarbons ofthe diesel class are between 150 and 400° C., typically between 180 and360° C.

Process

In the process according to the invention, the feedstock is subjected toketonisation, hydrodeoxygenation, and isomerization.

Isomerization Step of Unsaturated Carboxylic Acids and/or Esters

The isomerization may be carried out prior to the ketonisation step incase the feedstock comprises unsaturated carboxylic acids and/or alkylesters of unsaturated carboxylic acids, preferably unsaturated fattyacids and/or unsaturated fatty acid alkyl esters. Acidic catalystmaterials are used as the catalysts. Preferable the isomerizationcatalysts are aluminium phosphates, silica aluminium phosphates andzeolites, the catalyst preferably being a zeolite of the pentasil ormordenite type. The reaction temperature ranges from 150 to 350° C.,preferably from 200 to 290° C., the reaction pressure being between 0and 5 MPa, preferably between 0.1 and 2 MPa. Pressure is used to preventlighter components from evaporating. Water or a lower alcohol may beadded to the feedstock to suppress acid anhydride formation due todehydration or dealcoholation. It is preferable to add water when thefeedstock comprises unsaturated fatty acids and alcohol or when thefeedstock comprises esters of unsaturated fatty acids. Typically theamount of added water or lower alcohol is 0-8%, and preferably 1-3% byweight based on the total reaction mixture. The lower alcohol is C1-C5alcohol, and preferable alcohols are methanol, ethanol and propanol,with a greater preference given to those having the same alkyl group asthat of the starting fatty acid ester to be isomerized. Excess water(more than 10%) should be avoided in order to prevent estolideformation. This skeletal isomerization step may also be carried out inthe absence of water or lower alcohol. In case the reaction is performedas a batch reaction, the amount of the catalyst ranges from 0.01 to 30%by weight of the total reaction mixture, preferably from 0.5 to 10%, byweight. In the batch reactor, the reaction time is less than 16 hours,preferably less than 8 hours, particularly preferably less than 4 hours.In case a fixed bed reactor is used, the feed weight hourly spacevelocity (WHSV) is 0.1-100 l/h, where the amount of the feedstock isexpressed in grams per hour per grams of the catalyst.

Prehydrogenation Step

The isomerized product obtained above, or the non-isomerized feedstockmay be subjected to an optional prehydrogenation prior to theketonisation step to reduce side reactions caused by the double bonds.Prehydrogenation is performed as a separate process under mildconditions. Prehydrogenation is performed in the presence of aprehydrogenation catalyst, at a temperature between 50 and 400° C.,under a hydrogen pressure ranging from 0.1 to 20 MPa, the feed flow rateWHSV being between 0.1 and 10 l/h, the conditions preferably comprisingtemperatures between 100 and 300° C., hydrogen pressures ranging from 1to 15 MPa, WHSV being from 0.5 to 5 l/h, particularly preferableconditions comprising temperatures between 150 and 280° C., pressuresranging from 2 to 10 MPa, WHSV being from 1 to 3 l/h. Theprehydrogenation catalyst may contain metals of the Group VIII and/orVIA of the periodic system of the elements. The prehydrogenationcatalyst is preferably a supported Pd, Pt, Ni, Ru, Rh, NiMo or CoMocatalyst, the support being activated carbon, alumina and/or silica.

The optionally prehydrogenated product from the isomerization of fattyacids and/or fatty acid alkyl ester, or the optionally prehydrogenatedfeedstock is passed to the ketonisation step yielding as the product aketone with an increased hydrocarbon chain length. The obtained ketoneis hydrogenated in the HDO step to give saturated hydrocarbons.

Ketonisation Step

In the ketonisation step, the pressure ranges from 0 to 10 MPa,preferably from 0.1 to 5 MPa, particularly preferably from 0.1 to 1 MPa,whereas the temperature ranges between 100 and 500° C., preferablybetween 100 and 400° C., particularly preferably between 300 and 400°C., the feed flow rate WHSV being from 0.1 to 10 l/h, preferably from0.3 to 5 l/h, particularly preferably from 0.3 to 3 l/h. In theketonisation step metal oxide catalysts may be used. Typical metalsinclude Na, Mg, K, Ca, Sc, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Mo,Rh, Cd, Sn, La, Pb, Bi, and rare earth metals. These metal oxides may beon a support, typical supports being laterite, bauxite, titaniumdioxide, silica and/or aluminium oxide. The metal is preferablymolybdenum, manganese, magnesium, iron and/or cadmium, the support beingsilica and/or alumina. Particularly preferably the metal is molybdenum,manganese and/or magnesium as oxide in a catalyst without support. Nospecial catalysts are needed for the ketonisation of metal salts offatty acids (soaps), since the metal present in the soap promotes theketonization reaction.

Hydrodeoxygenation

In the HDO step of the invention, the ketone and hydrogen gas arereacted under a pressure ranging between 0.1 and 20 MPa, preferablybetween 1 and 15 MPa, particularly preferably from 2 to 10 MPa, thetemperature being from 100 to 500° C., preferably from 150 to 400° C.,particularly preferably from 200 to 350° C., the flow rate WHSV varyingfrom 0.1 to 10 l/h, preferably from WHSV 1 to 5 l/h, and particularlypreferably from WHSV 1 to 3 l/h. In the HDO step, special catalystscontaining a metal of the Group VIII and/or VIA of the periodic systemof the elements, on a support may be used. The HDO catalyst ispreferably a supported Pd, Pt, Ni, NiMo or CoMo catalyst, the supportbeing activated carbon, alumina and/or silica.

In a preferable embodiment, the reaction product obtained after the HDOstep is purified for instance by stripping with steam, or with asuitable gas such as a light hydrocarbons, nitrogen or hydrogen. It ispreferable for the process to remove impurities and water as efficientlyas possible prior to the hydro isomerization step and/or finishing step.

In case the feedstock is already subjected to the isomerization of fattyacids and/or fatty acid alkyl esters, only optional finishing andseparation steps are performed after the HDO and the optionalpurification steps.

Isomerization Step as Hydroisomerization

In case the isomerization of carboxylic acids and/or carboxylic acidalkyl esters was not carried out, a hydroisomerization step is carriedout after the ketonisation, HDO and optional purification steps. In thiscase the hydrogenated product obtained from ketonisation followed byhydrodeoxygenation, and optional paraffinic additional feed are passedto the hydroisomerization reactor to react with hydrogen gas in thepresence of a isomerization catalyst. In the hydroisomerization step,the pressure ranges from 0 to 20 MPa, preferably from 1 to 15 MPa, andparticularly preferably from 4 to 10 MPa. The temperature ranges between100 and 500° C., preferably between 200 and 400° C., and particularlybetween 250 and 370° C. The flow rate WHSV in between 0.1 and 10 l/h,preferably between 1 to 5 l/h, and particularly preferably between 1 and3 l/h. In the hydroisomerization step, special isomerization catalystscontaining molecular sieves and metals of the Group VIII of the periodicsystem of the elements, for instance Ni, Pt, and Pd, may be used.Alumina and/or silica may be used as supports.

Dewaxing Step

Following ketonisation, HDO and hydroisomerization steps of thefeedstock, an optional dewaxing may be performed either catalytically oras solvent-based dewaxing. An optional dewaxing may also be carried outafter the isomerization, ketonisation and HDO steps of unsaturated fattyacid and/or fatty acid alkyl ester feedstock.

In the catalytic dewaxing, hydrogen gas and the hydrogenated component,as well as the optional paraffinic additional feed react in the presenceof a dewaxing catalyst. Zeolite catalysts comprising metals of the GroupVIII of the periodic system of the elements such as Ni, Pt or Pd areused as dewaxing catalysts. In the dewaxing step, the pressure variesfrom 0.1 to 20 MPa, the temperature being between 100 and 500° C.

In the solvent-based dewaxing, linear paraffinic waxes are separated bydissolving the oil (hydrocarbon product) in a mixture of solvents, forinstance methylethyl ketone and toluene. In the process, the solvent andthe feed are passed in counter current manner and thus mixed. Themixture of oil and solvent is introduced to a cooling unit. Coolingresults in the crystallization of the linear paraffinic waxes, whereasbranched paraffins remain as oily liquids. The temperature used dependson the target low temperature properties of the product, the pour pointof the final product decreasing as the temperature in dewaxing isdecreased. Wax crystals are filtered from the mixture, collected forfurther processing, and the solvent is separated by evaporation from thebase oil. Solvent-based dewaxing is also suitable for fatty acids and/orfatty acid alkyl esters after isomerization and prehydrogenation of thedouble bonds. Linear fatty acids and/or linear fatty acid alkyl estersare thus separated from the mixture of branched and non-crystallizablecompounds by dissolving the feed for instance in hexane, and cooling asdescribed above.

Finishing Step

The above obtained and optionally dewaxed product may optionally befinished for removing any double bonds and aromatics. In hydrofinishing,the finishing is performed using hydrogen in the presence of a catalyst,the pressure ranging from 1 to 20 MPa, preferably from 2 to 15 MPa, andparticularly preferably from 3 to 10 MPa, and the temperature rangesbetween 50 and 500° C., preferably between 200 and 400° C., andparticularly preferably between 200 and 300° C. In the hydrofinishing,special catalysts containing metals of the Group VIII of the periodicsystem of the elements, and a support may be used. The hydrofinishingcatalyst is preferably a supported Pd, Pt, or Ni catalyst, the supportbeing alumina and/or silica. Finishing may also be achieved by removingpolar components using adsorption materials, such as clay or molecularsieves.

Following optional finishing, the product is passed to a distillationand/or separation unit in which product components boiling overdifferent temperature range and/or product components intended fordifferent applications are separated from each other.

If desired, the hydrocarbon component obtained as the product, oranother suitable hydrocarbon may be used as a diluent in various stagesof the process of the invention, such as in the ketonization, HDO and/orisomerization steps for increasing the conversion and/or selectivityand/or for controlling the exothermal nature of the reactions.

A fixed bed reactor, for instance the trickle bed reactor of the priorart is preferably used in prehydrogenation, HDO, hydroisomerization, andhydrofinishing steps.

Product

The process according to the invention yields a high quality branchedand paraffinic hydrocarbon component suitable as a base oil or base oilcomponent. The base oil product has excellent viscosity and lowtemperature properties. The process according to the invention alsoyields typically as a by-product a branched and paraffinic hydrocarbonproduct suitable for diesel fuel pool. The diesel component containstypically some short carbon-carbon side branches, resulting in anexceptionally low cloud point and cold filter plugging point but still agood cetane number. In addition, a hydrocarbon component suitable to beused as a solvent, gasoline and/or a component of gasoline is obtainedas a by-product. All products are preferably of biological origin.

A branched, saturated and paraffinic hydrocarbon component is the mainproduct in the process according to the invention, particularly when theketonisation and hydrodeoxygenation steps are carried out prior toisomerization. A branched, saturated and paraffinic hydrocarboncomponent containing high amounts of cycloparaffins is obtained whencarboxylic (fatty) acids are isomerized prior to the ketonisation andhydrodeoxygenation steps.

Feedstocks, which are preferably derived from biological startingmaterials, have a substantial effect on the composition and distillationrange of the product. For instance feedstocks consisting of fatty acidsmay be fractionated by distillation to give narrow fractions to betailored for various applications. For feedstocks having hydrocarbonchains of C16, C18, C20 and C22, typical carbon numbers of products arerespectively C31, C35, C39, and C43. Narrow product fractions areobtained since the distillation range of the product mainly depends onthe length of the hydrocarbon chain of the feedstock. Base oils withnarrow distillation ranges obtained according to the invention haveextremely low volatilities when compared to corresponding products ofthe prior art.

Carbon number range of the base oil of the invention is extremelynarrow, typically no more than 5 carbons wide. Most typical structuresand carbon number ranges (C31-C35) of the base oils 1 and 2 produced bythe process of the invention (4-6 cSt/100° C.) are presented in Table 2.Carbon number depends on the carbon number of the feedstock. Mosttypical carbon numbers are shown bold-faced.

TABLE 2 Carbon numbers and structures of the base oils of the inventionCarbon number Base %, by oil FIMS Structure 1 C31/ C33/ C35 acycliccompo- nent about 90% mono- naph- thenes about 10%

2 C31/ C33/ C35 acyclic compo- nent about 25% mono- naph-thenes about50% di- naph- thenes about 25%

Base oils of biological origin shown in Table 2 are produced as follows:

1. Stearic acid fraction is ketonised, hydrodeoxygenated, andhydroisomerized.

2. Unsaturated fatty acid is isomerized, ketonised, andhydrodeoxygenated.

Using feedstocks with different hydrocarbon chains, the molecular massesof the products may be increased to reach viscosity ranges required fordifferent applications by means of the ketonisation reaction. With theprocess of the invention, lighter hydrocarbon products such as solvents,gasoline, and diesel fuels may be produced from feedstocks of shorterhydrocarbon chains.

Saturated hydrocarbons are classified according to the carbon andhydrogen atoms by field ionization mass spectrometry (FIMS) method asfollows:

1 C(n).H(2n+2) paraffins

2 C(n).H(2n) mononaphthenes

3 C(n).H(2n−2) dinaphthenes

4 C(n).H(2n−4) trinaphthenes

5 C(n).H(2n−6) tetranaphthenes

6 C(n).H(2n−8) pentanaphthenes

In Tables 2 and 3, the percentages (%, by FIMS) refer to the groups ofcompounds determined according to said method.

In Table 3 are presented typical carbon number ranges (C25-C35) andcompositions of synthetic (GTL) and mineral oil (VHVI and Slack Wax)base oils, belonging to the same viscosity class of about 4-6 cStmeasured at 100° C. Structures of naphthenes are examples of differentcompound types. The average carbon numbers are shown bold-faced.

Products shown in Table 3 are produced as follows:

1. GTL is a hydroisomerized Fischer-Tropsch waxy fraction derived fromnatural gas

2. Slack Wax is a hydroisomerized Slack Wax fraction derived from crudeoil

3. VHVI is a hydrocracked and hydroisomerized base oil derived fromcrude oil

TABLE 3 Carbon numbers and expected typical structures of synthetic baseoils and base oils derived from crude oil Carbon number Base %, by oilFIMS Structure 1 GTL C25- C35, C29 acyclic compo- nent about 90% mono-naph- thenes about 10%

2 SLACK WAX C25- C35, C28 paraf- finic compo- nent about 70% mono- naph-thenes about 25% fused dinaph- thenes about 5%

3 VHVI C25- C35, C29 paraf- finic compo- nent about 40% mono- naph-thenes about 35% fused dinaph- thenes about 15% fused trina- phthenesabout 5% fused tetra/ pentana- phthenes about 2-5%

With respect to carbon number and molecular structure, base oils of theinvention differ from products of the prior art, as may be clearly seenfrom Tables 2 and 3. In case the isomerization is based on the doublebonds of C18 fatty acid skeleton (structure 2 in Table 1), the structureof the branched, saturated hydrocarbon product obtained using theprocess according to the invention is different from the one obtainedfor example when hydroisomerizing C25-C35 paraffins in Slack and GTLwaxes. In the present case the branches are mainly in the middle of thelong hydrocarbon chain, due to the common ω9 olefinic unsaturationpositions responsible of branching. In Slack and GTL waxes (structures 1and 2 in Table 3), the branches are mainly near the ends of thehydrocarbon main chain. There are typically alkyl branches having carbonnumbers 1-4 within the hydrocarbon chain of the product. With respect tothe branching site, the branched components are mixtures of differentisomers. Branches more in the middle of the hydrocarbon chain lower thepour point considerably more than those at the ends of the chain.

In addition to the location of the branches, also the number of branchesaffects the pour point. The pour point being lowered by increasingnumber of branches, but at the same time also the viscosity index isreduced. It is known that an optimum correlation between the viscosityindex and pour point is attained with only few branches present in themain hydrocarbon chain. In the process of the invention where theisomerization is based on the double bonds of C18 fatty acid skeleton,the number of branches is limited by the number of double bonds in thefeedstock, and thus the base oil may not be branched too much to causethe VI to be reduced near the lower limit. In a similar manner, loweringof the pour point is limited by the number of double bonds in thefeedstock.

In case the isomerization is based on hydroisomerization, such as of theC31/C33/C35 wax of hydrodeoxygenated ketone (structure 1 in Table 1),the structure of the branched, saturated hydrocarbon product obtainedusing the process according to the invention resembles to the oneobtained hydroisomerizing C25-C35 paraffins in SW and GTL wax. In bothpresent cases of the invention, the length of the hydrocarbon chain isthough higher, typically from C31 to C35 and narrower than those oftechnically known base oils. Due to relatively long hydrocarbon mainchain and controlled level of branching, the viscosity and coldproperties of the product of invention are very good: the kinematicviscosity (KV100) is about 5 cSt and VI above 150 even though pour pointis decreased to near −20° C.

Naphthenes of the final product of the invention are mononaphthenes andnon-fused dinaphthenes. In the Slack wax and VHVI products of the priorart, the dinaphthenes are mainly fused. The VI of fused naphthenes ispoorer than that of non-fused naphthenes. In addition, it is known thatthe non-fused naphthene rings are desirable as components of base oilssince their VI is reasonably high but the pour point low. In the VHVIproducts of the prior art (structure 3 in Table 3), in addition tomononaphthenes there are polycyclic naphthenes with 3-5 rings typicallynot present in the product of the invention. These are formed as aresult of cracking and hydrogenation of naphthenes and aromaticcompounds of the mineral crude oil based feed.

In addition to pour point and viscosity index, the relationship ofisoparaffins and 1-2 ring naphthenes to 3-6 ring naphthenes seem to playthe major role in cold cranking. If too high amount of multiringnaphthenes are present, they give higher CCS-30 values since they arepresent as an extremely viscous liquid. Furthermore, if normal paraffinsare present after hydroisomerization, they give high CCS-30 values bycrystallization and thus inhibiting the liquid to flow.

The base oil of biological origin according to the invention comprises aproduct produced from starting materials of biological origin. The baseoil comprises branched hydrocarbons having carbon number at least C18.Said product contains not more than 20%, preferably not more than 10%,and particularly preferably not more than 5%, by weight, and at best notmore than 1% by weight of linear paraffins, and at least 90%, preferablyat least 95%, and particularly preferably at least 97%, by weight, andat best 99% by weight of saturated hydrocarbons.

Base oils of the invention comprise mono and dinaphthenes, but nopolycyclic naphthenes, the dinaphthenes thereof being non-fused. Basedon the FIMS analysis, the product of the invention containsmononaphthenes more than 5%, preferably 5-20%, particularly preferably5-15%, and at best 5-10%; and less than 1.0%, preferably less than 0.5%,and particularly preferably less than 0.1% of polycyclic naphthenesmeasured by FIMS.

For base oils of the invention, having kinematic viscosity KV100 of 4-7mm²/s, the viscosity index is at least 115 and preferably at least 120,particularly preferably at least 150, and at best at least 160 (ASTM D2270) and pour point lower than −9° C., preferably lower than −12° C.and particularly preferably lower than −15° C. (ASTM D 97/5950).

Low temperature dynamic viscosity, CCS-30, for base oil is no more than29.797*(KV100)^(2.7848) cP, preferably no more than34.066*(KV100)^(2.3967) cP; CCS-35 is no more than36.108*(KV100)^(3.069) cP, preferably no more than50.501*(KV100)^(2.4918) cP measured by method ASTM D 5293; pour pointbeing not over −9° C., preferably not over −12° C. and particularlypreferably not over −15° C. (ASTM D 97/5950).

For base oil of the invention the volatility of product, having KV100from 3 cSt to 8 cSt, is no more than 2271.2*(KV100)^(−3.5373)% by weightas determined by the method of DIN 51581-2 (Mathematical Noack methodbased on ASTM D 2887 GC distillation).

Width of the carbon number range of base oils of the invention is nomore than 9 carbons, preferably no more than 7 carbons, particularlypreferably no more than 5 carbons, and at best 3 carbons (FIMS). Morethan about 50%, preferably more than 75% and particularly preferablymore than 90% by weight of the base oil contain hydrocarbons belongingto this narrow carbon number range.

Distillation range of base oils of the invention is no more than 155°C., preferably no more than 100° C., particularly preferably no morethan 70° C., and at best no more than 50° C. (determined by the methodof ASTM D 2887, distillation points D10 and D90).

Sulfur content of said base oil of the invention is less than 300 ppm,preferably less than 50 ppm, and particularly preferably less than 1ppm, (ASTM D 3120).

Nitrogen content of said base oil of the invention is less than 100 ppm,preferably less than 10 ppm, and particularly preferably less than 1ppm, (ASTM D 4629).

Base oils of the invention, based on biological starting materials,contain carbon ¹⁴C isotope, which may be considered as an indication ofthe use of renewable raw materials. Typical ¹⁴C isotope content(proportion) of the total carbon content in the product, which iscompletely of biological origin, is at least 100%. Carbon ¹⁴C isotopecontent is determined on the basis of radioactive carbon (carbon ¹⁴Cisotope) content in the atmosphere in 1950 (ASTM D 6866). ¹⁴C isotopecontent of the base oil according to the invention is lower in caseswhere other components besides biological components are used in theprocessing of the product, said proportion being, however, more than50%, preferably more than 90%, particularly preferably more than 99%. Inthis way, even low amounts of base oil of biological origin may bedetected in other types of hydrocarbon base oils.

The cetane number of the diesel product obtained with the process of theinvention, is more than 40, preferably more than 55, and particularlypreferably more than 70. It contains more than 60%, preferably more than99% by volume, of paraffins, and less than 30%, preferably less than 1%by volume, of aromatics, based on the IP-391 method. The productcomprises less than 40%, preferably less than 10%, by weight, of linearn-paraffins. The cloud point of the diesel component is less than 0° C.,preferably less than −15° C., and particularly less than −30° C.Typically, the diesel product obtained is totally of biological origin.In the product of the invention, there are branches formed bycarbon-carbon bonds, this structure resulting in a very low cloud point.

ADVANTAGES OF THE INVENTION

The process of the invention allows particularly for the use ofrenewable starting materials of biological origin, containingheteroatoms, for producing base oils, but also diesel and gasolinecomponents. In addition to traditional crude oil, a completely new rawmaterial source for high-quality branched paraffinic base oils isprovided according to the invention. Also carbon dioxide emissionscontributing to the greenhouse effect may be reduced by using renewableraw material sources instead of non-renewable ones.

According to the process of the invention, base oil containing onlycarbon and hydrogen is obtained, the stability of said base oil in humidconditions being higher than that of esters or other base oilscontaining heteroatoms. A paraffinic hydrocarbon component is notdecomposed as easily as esters that form corrosive acids. A nonpolar andfully saturated hydrocarbon component free of sulfur is obtained usingthe process of the invention by removing oxygen of ketones, and theheteroatoms of any impurities of the feedstock in the HDO step. In theisomerization step, the carbon chain is branched, thus improving lowtemperature properties, that is, the pour point is lowered,low-temperature fluidity enhanced and filterability at low temperaturesis improved. Solid wax is converted to oily hydrocarbon having viscosityindex (viscosity-temperature-dependence) very suitable for top-tier baseoils without blending limitations, and further, it is compatible withlubricant additives.

With the process of the invention, high-quality saturated base oilhaving a low pour point may be produced, said base oil being also veryuseful at low temperature conditions. The product is typically free ofsulfur, the viscosity index thereof being preferably at least 120, andthus it may also be suitably used in applications of Group III baseoils.

Composition, properties and boiling range of the product are alsostrongly influenced by the starting material of biological origin. Thestarting material may be distilled to fractions according to carbonnumbers. According to the invention, branched paraffinic base oil havingnarrow boiling ranges and different physical properties may be processedfrom these fractions. Typical carbon number ranges of the productcomponents are as follows: gas C1-C4, gasoline C5-C10, diesel C11-C26,and base oil having carbon number of at least C18. Distillation range ofbase oil produced from a feedstock having a single carbon number is thenarrowest.

Narrow distillation range indicates that the product does not containinitial light fraction, meaning molecules considerably lighter than theaverage, which can be seen as decreased volatility of the product,resulting in reduced emissions and reduced use of lubricants inpractical applications. The “tail” composed of the heavier components,meaning molecules considerably heavier than the average, is also missingfrom the product. This results in excellent low temperature propertiesof the product.

For the base oil of the invention, the carbon number and distillationrange are governed by the feedstock composition. For base oils of theprior art, the distillation range is adjusted by distilling the productto obtain a fraction having the desired kinematic viscosity. It ispreferable that lubricants have base oils with narrow carbon numberdistribution and thus narrow distillation range, so that lubricatingoils contain molecules of similar sizes behaving in a similar way underdifferent conditions.

The base oil according to the invention has high viscosity index, whichleads to a significantly decreased need of high price Viscosity IndexImprover (VII) or in other terms Viscosity Modifier (VM). It is commonlyknown, that the VII is an additive, which causes highest amount ofdeposits in vehicle engines. In addition, reduction of the amounts ofVII results in significant savings in costs.

Also, because the base oil is non-toxic, contains no sulfur, nitrogen oraromatic compounds typically present in the conventional mineral oilbased products, it may more safely be used in applications where the enduser is exposed to oil or oil spray.

Moreover, response of the base oil according to the invention isextremely high for antioxidants and pour point depressants, and thus thelife time of the lubricating oils are longer and they can be used in thecolder environment than lubricants based on the conventional base oils.

Even though the branched, saturated hydrocarbon product is produced fromsaturated and unsaturated natural fatty acids, it contains no oxygen,and thus its hydrolytic stability is much higher than that of syntheticester base oils. Due to the lack of ester bonds, also the formation ofacidic degradation products is minimized. In addition, the oxidationstability of the saturated base oil is higher than that of ester baseoil containing unsaturated fatty acid structural units.

Compared to esters, the base oil of the invention is more compatiblewith conventional base oils derived from crude oil, base oils obtainedfrom Fischer-Tropsch process, and with hydrocarbon base oils, as wellwith lubricant additives. Moreover, it is compatible with elastomers,and thus it can be used in modern vehicle engines without modifications.

An additional advantage of the base oil according to this invention isthat it fulfils the API group III base oil specifications. Therefore itcan be used in engine oil formulations like other group III base oilsaccording the same interchanging rules without need to perform newengine tests.

The base oil of the invention is preferably based on renewable naturalresources. Starting materials of the process of the invention areavailable all over the world, and moreover, the utilization of theprocess is not limited by significant initial investments in contrastfor instance to the GTL technology.

The products of the inventive process are carbon dioxide neutral withrespect to the use and disposal thereof, that is, they will not increasethe carbon dioxide load of the atmosphere in contrast to productsderived from fossil starting materials.

Further advantages of the invention relate to diesel fuel component ofbiological origin, which has excellent low temperature properties andcetane number compared to those of solutions of the prior art, wherecomponents based on fatty acid methyl esters are used. Problemsassociated with low temperature properties have been avoided byisomerizing waxy n-paraffins derived from fatty acids to giveisoparaffins.

The middle distillate diesel fuel component obtained is a high-qualityhydrocarbon component of biological origin particularly suitable as acomponent for diesel fuel, as isoparaffinic solvent, and as lamp oil,the cetane number thereof being even above 70, the cloud point being aslow as below −30° C. Fouling of the engine may be expected to be reducedin comparison to fuels of biological origin already known in the art,said fuels containing incompletely burning ester components. Moreover,the density of the composition is lower. The composition requires nochanges of the automobile technology or logistics. Higher energy contentof the biological component per unit volume compared to products basedon esters may also be mentioned as an advantage.

With the optional prehydrogenation step side reactions of double bondsof hydrocarbon chains may be reduced. Side reactions, such aspolymerization, ring formation and aromatization cause coke formation onthe catalyst, thus reducing its service life. Ring formation andpolymerization change also viscosity properties of the hydrocarboncomponents. Moreover, said prehydrogenation results in improved yieldsof the final base oil product.

In addition to hydrocarbon chain lengthening also oxygen may be removedfrom the feedstock as carbon dioxide with the ketonization reaction,which is favorable for the process to minimize hydrogen consumption.With the isomerization, low temperature properties of the product may beimproved without interfering with viscosity properties.

With the solution of the invention, high hydrogen partial pressure maybe maintained throughout the whole process, and keep levels ofimpurities low. Carbon monoxide, carbon dioxide and water contents maybe lowered to such an extent that light stripping in the HDO stage or ina separate gas/liquid separation vessel is sufficient to remove residualimpurities prior to isomerization.

Advantages of the invention also include protection of the isomerizationcatalyst, thus preventing the deactivation thereof.

The properties of the hydrocarbon components produced with the processaccording to the invention are excellent, and moreover, distillationranges of products produced from fatty acids with a specific carbonnumber are considerably narrower that those of VHVI base oils. Theproducts are well suited as base oils without blending limitations, andfurther, the products are also compatible with lubricant additives.

EXAMPLES

The invention is now illustrated by means of the following exampleswithout wishing to limit the scope of the invention thereby. Propertiesof the hydrocarbon components prepared in the examples are presented inTable 4. Similarly, properties of some of the base oils of the prior artare shown in Table 5. It is however clear that the invention is notlimited to embodiments described in the examples.

Example 1 Preparation of a Hydrocarbon Component from Stearic AcidFraction (C₁₇H₃₅COOH)

A mixture of plant oils (linseed, soybean, and rapeseed oils) waspretreated by hydrolysis and distillation to obtain fatty acid fractionsaccording to carbon numbers. The C18 acid fraction thus obtained wasused as the feed, the fraction being diluted with a paraffinic dieselfuel of biological origin. C18 acid content of the feedstock thusobtained was 31%, by weight. Double bonds of the feedstock wereselectively prehydrogenated, and the stearic acid was continuouslyketonised at atmospheric pressure, in a tubular reactor using a MnO₂catalyst. Temperature of the reactor was 370° C., the WHSV of total feedbeing 3 l/h. 22% by weight of 18-pentatriacontanone, or stearone, in adiluent was obtained as the ketonisation product.

In the next step, the stearone/diluent mixture obtained above washydrodeoxygenated in a high pressure Parr reactor using a dried andactivated NiMo/Al₂O₃ catalyst, to give linear paraffins. The ketone washydrogenated at 330° C., under a pressure of 5 MPa, mixing at 300 rpmuntil no ketone peak was detected in the FTIR spectrum. 71% by weight oflinear C35 paraffin was obtained from stearic acid.

The paraffin wax obtained above was isomerized in a Parr reactor to givea branched paraffin of the base oil class using a reduced Pt molecularsieve/Al₂O₃ catalyst. Preheated mixture of the paraffin/diluent wasisomerized under a hydrogen pressure of 3 MPa and at 340° C. until apour point of −6° C. was obtained. Finally, light fractions weredistilled from the product at reduced pressure, followed by finishing ofthe paraffinic product by filtering through kieselguhr. Hydrocarboncomponents may be produced in a similar way from other fatty acids anddicarboxylic acids.

Example 2 Preparation of a Hydrocarbon Component from Fatty AcidsDerived from Palm Oil

Palm oil was hydrolyzed. Fatty acids derived from palm oil were used asthe feedstock following selective prehydrogenation of the double bondsof said fatty acids. After hydrogenation, the fatty acid composition wasas follows: C14 1%, C16 44%, C18 54%, and C20 1%, all percentages beingby weight. The fatty acids were ketonised as in Example 1. Followingketonization, the solvent was distilled off, yielding a product with thefollowing composition: C15COC15 ketone, 10.4%, C15COC17 ketone, 42.1%,and C17COC17 ketone, 43.6%, by weight.

The ketone mixture obtained from the ketonisation stage washydrodeoxygenated in a Parr reactor using a dried and activatedNiMo/Al₂O₃ catalyst to give linear paraffins. Hydrodeoxygenation wascarried out under a pressure of 3.3 MPa, at 330° C., mixing at 300 rpm.Linear paraffin with the composition: C33 chain 41.8%, C34 chain 2.1%,and C35 chain 43.8% by weight was obtained from palm oil.

The linear paraffin wax obtained in the HDO step was isomerized in aParr reactor to give branched paraffins of the base oil class using areduced Pt molecular sieve/Al₂O₃ catalyst. Isomerization was performedat 340° C., under a hydrogen pressure of 3 MPa until the pour point ofthe product was below −15° C. Finally, light fractions were distilledoff under reduced pressure.

Palm oil also contains C16 and C18 fatty acids, the hydrocarboncomponent thus having a wider distillation range and a lower kinematicviscosity compared to the product of Example 1. Hydrocarbon componentsmay also be produced in a similar way from other plant and fish oils,and animal fats.

Example 3 Preparation of a Hydrocarbon Component from Methyl Esters ofFatty Acids Derived from Animal Fats

Purified animal fat was transesterified under basic conditions withmethanol at 70° C., under a pressure of 0.1 MPa, in the presence of asodium methoxide catalyst in two steps, thus producing methyl esters offatty acids. The reaction mixture was purified by washing with acid andwater, and the mixture of fatty acid methyl esters was dried. The fattyacid composition of the mixture of methyl esters derived from animal fatwas as follows: C14:0 2%; C16:0 23%, C16:1 3%, C18:0 13%, C18:1 40%,C18:2 11%, C18:3 1% by weight.

The mixture of fatty acid methyl esters obtained above was used as thefeedstock of the process, diluted with paraffinic diesel of biologicalorigin. The fatty acid methyl ester content of the feedstock was 30% byweight, the feedstock being continuously ketonised in a tubular reactionas described in Example 1. Both saturated and unsaturated ketones wereobtained as the product. Their carbon numbers were as follows: 10% ofC21-C28 ketones, 3% of C29 ketone, 10% of C31 ketone, 33% of C33 ketone,and 20% by weight of C35 ketone.

The ketone mixture was first hydrodeoxygenated a Parr reactor asdescribed in Example 2, followed by isomerization according to Example2. Hydrocarbon components may also be produced in a similar manner frommethyl esters derived from plant and fish oils. Service life of theketonization catalyst may be extended by using less corrosive methylesters instead of fatty acids.

Example 4 Preparation of a Hydrocarbon Component from Metal Stearates

A metal stearate (CH₃(CH₂)₁₆COO)₂Mg was ketonised under atmosphericpressure in a Parr reactor at 340° C. and with mixing rate of 300 rpm.Stearone, or C35 ketone, obtained as the product was hydrodeoxygenatedand isomerized as described in Example 1. The product thus obtainedcorrespond the product of Example 1. Hydrocarbon components may also beproduced in a similar manner from other metal salts of fatty acidsderived from plant oils, animal fats and fish oils, as well as frommetal salts of fatty acids obtained by saponification of plant and fishoils or animal fats. No special catalyst is needed for the ketonizationin case metal salts are used.

Example 5 Preparation of a Hydrocarbon Component from Carboxylic Acidsof Tall Oil

Distilled tall oil fatty acids were isomerized in a Parr high-pressurereactor with mordenite type zeolite. Tall oil fatty acids, 5 wt-% of thecatalyst and 3 wt-% of water, calculated of total reaction mixture, wereplaced in a reactor and air was removed from the autoclave with purgingnitrogen. The mixture was stirred with 300 rpm. The reactor was heatedto 280° C. and kept under nitrogen atmosphere of 1.8 MPa for 6 hours.After cooling, the reaction mixture obtained was taken from theautoclave, and the zeolite was filtered off. The filtrate was distilledunder reduced pressure to yield monomeric acids.

The monomeric acids thus obtained were placed in an autoclave, anddouble bonds were hydrogenated at 150° C. with a catalyst containing 5wt-% Pd on carbon under hydrogen atmosphere of 2 MPa until the reactionwas complete. Catalyst amount was 2 wt-% of monomeric acid. Then, thereaction mixture was cooled, and the catalyst was filtered off.

The obtained crude branched chain fatty acids were subjected to aconventional solvent fractionation procedure to yield isomerized fattyacids. To the crude branched chain fatty acids, about 2-fold amount byweight of hexane was added. After this mixture was cooled to −15° C.,the resulting crystals of non-isomerized fatty acids were filtered off.Then, the hexane was distilled off from the filtrate to yield purifiedisomerized fatty acids.

The isostearic acid was diluted with a paraffinic diesel of biologicalorigin in a ratio of 30/70%, by weight. The mixture thus obtained wascontinuously ketonised at atmospheric pressure in a tubular reactorusing a MnO₂ catalyst. The temperature of the reactor was 370° C., theWHSV being 1.7. A mixture of isomerized ketones was obtained as theproduct.

The mixture of isomerized ketones was hydrogenated in a HDO step in aParr reactor as in Example 2. Solvents were distilled from the finalproduct under reduced pressure. Thereafter, the product was subjected tosolvent dewaxing to remove linear paraffins, and finally, the paraffinicproduct was finished by filtering through kieselguhr. Mainly branchedparaffins were obtained as the final product. Hydrocarbon components mayalso be produced in a similar way from other isomerized fatty acids orfrom isomerized methyl esters of fatty acids of plant, animal and fishorigin.

Example 6 Preparation of a Hydrocarbon Component from Tall Oil FattyAcids and Dicarboxylic Acids

Distilled mixture of fatty acids from tall oil was isomerized andprehydrogenated as described in Example 5. The isostearic acid fractionthus obtained and the C6 dicarboxylic acid (adipic acid) were mixed in amolar ratio of 1:3, and the mixture was ketonised under atmosphericpressure in a Parr reactor using a MgO catalyst at 340° C., with mixingrate of 300 rpm.

The ketone mixture was hydrogenated in the HDO step in a Parr reactor asin Example 1, and light fractions were separated by distillation fromthe final product under reduced pressure. In comparison to otherExamples, branched paraffins having longer chains were obtained asproducts. Hydrocarbon components may also be produced in a similarmanner from other fatty acids or fatty acid methyl esters of plant,animal and fish origin and dicarboxylic acids. Either the fatty acids,or alternatively the wax obtained after ketonisation andhydrodeoxygenation may be subjected to isomerization.

TABLE 4 Properties of the products produced in Examples 1-6 Examp ExampExamp Examp Examp Analysis 1 2 3 5 6 Method KV100 (mm²/s) 5.2 4.3 5.86.5 16.4 ASTM D445 KV40 (mm²/s) 23.0 18.3 27.7 34.0 150.5 ASTM D445 VI,( ) 164 153 159 148 115 ASTM D2270 Pour point (° C.) −6 −21 −18 −12 −12ASTM D5950 GC-distillation (° C.) ASTM D2887 10% 419 375 455 50% 475 457481 90% 486 474 497 GC-Noack volatility, wt-% 5.8 12.5 4.2 DIN 51581-2Molecular distribution, wt-% n-Paraffins <1 <1 GC i-Paraffins 88 31 FIMSMononaphthenes 12 49 FIMS Dinaphthenes 0 20 FIMS Other naphthenes 0 0FIMS Sulfur, ppm <1 1 ASTM D3120/D4294 Nitrogen, ppm <1 <1 ASTM D4629

TABLE 5 Properties of the base oils of the prior art. API API GpIII,GpIII, API API HC- HC- GpIII, GpIV, Analysis CDW CDW SW PAO Method KV100(cSt) 4.29 6.00 4.0 5.7 ASTM D445 KV40 (cSt) 20.0 33.1 16.8 30 ASTM D445VI 122 128 140 135 ASTM D2270 Pour point (° C.) −18 −12 −21 <−63 ASTMD5950 CCS at −30° C. 1750 4100 2300 ASTM D5293 (cP) CCS at −35° C. 31007800 1560 3850 ASTM D5293 (cP) GC distillation ASTM D2887 (° C.) 10% 395412 394 50% 421 459 421 90% 456 513 459 GC-Noack, w-% 13.3 5.8 12.5 DIN51581-2 Molecular distribution, wt-% Aromatics 0.0 0.0 0.0 0.0 ASTMD2549 Paraffins 37.0 26.8 72.4 100 FIMS Mononaphthenes 37.3 39.3 23.9 0FIMS Dinaphthenes 16.1 20.3 3.5 0 FIMS Other naphthenes 9.8 13.6 0.2 0FIMS Sulfur, ppm <0.2 <0.2 <1 ASTM D3120/ D 4294 Nitrogen, ppm <1 <1 <1ASTM D4629 HC-CDW = hydrocracked, catalytically dewaxed base oil

Example 7 Preparation of a Hydrocarbon Component from Fatty AcidsDerived from Palm Oil

Palm oil was hydrolyzed. Fatty acids derived from palm oil were used asthe feedstock following selective prehydrogenation of the double bondsof said fatty acids. The fatty acids were vaporized with nitrogen purgein a separate vaporizer unit and ketonised continuously at atmosphericpressure, in a tubular reactor using a MnO₂ as catalyst. Temperature ofthe reactor was 380° C., the WHSV of the feed being 1 l/h-1.

The C31, C33, C35 ketone mixture obtained from the ketonisation stagewas hydrodeoxygenated continuously in a tubular fixed bed reactor usinga dried and activated NiMo/Al₂O₃ catalyst to give linear paraffins.Hydrodeoxygenation was carried out under a pressure of 4 MPa (40 bar),at 270° C. and with WHSV of 1 l/h.

The linear paraffin wax obtained in the HDO step was isomerizedcontinuously in a tubular fixed bed reactor using a reduced Pt molecularsieve/Al₂O₃ catalyst to give branched paraffins using a reduced Ptmolecular sieve/Al₂O₃ catalyst. Isomerization was performed at 340° C.,under a hydrogen pressure of 4 MPa until the pour point of the productwas below −15° C. Finally, light fractions were distilled under reducedpressure and separated.

Hydrocarbon components may also be produced in a similar way from otherplant and fish oils, and animal fats.

TABLE 6 Properties of the products in example 7. baseoil diesel baseoil356- 170- Method Analysis >413° C. 413° C. 356° C. ASTM D 4052 Density @15° C., kg/m3 821.8 810.1 775.3 ASTM D 5950 Pour Point, ° C. −23 −32ASTM D 5771 Cloud Point, ° C. −6.8 −24.7 <−50 EN 116 Cold Filter PlugPoint, ° C. <−45 ENISO 2719 Flash point PMcc, ° C. 84.0 1QT cetanenumber 73 ASTM D 5293 CCS-30, mPas 1780 CCS-35, mPas 2920 690 ASTM D 445kV40, cSt 25.7 10.9 2.4 ASTM D 445 kV100, cSt 5.4 2.9 ASTM D 2270 VI 153126 ASTM D 2887  0.5%, ° C. 171   10%, ° C. 431 355 199   50%, ° C. 453384 267   90%, ° C. 497 415 339 99.5%, ° C. 361 DIN 51581-2 GC Noack 4.433.1 FIMS paraffins 90.5 mononaphthenes 9.5 dinaphthenes 0 othernaphthenes 0 EN12916 Monoaromatics % 0.2 Diaromatics % <0.1 Triaromatics% <0.02 ASTM D 3120 S, mg/kg 0 0 1.1 ASTM D 4629 N, mg/kg 0 0 <1 ENISO12205 Oxidation Stability (g/m3) max 1

Example 8 Determination of the Biological Origin of the HydrocarbonComponent

Hydrocarbon component of biological origin was weighed into mineral oilbased Group III base oil, and mixed thoroughly. For the first sample,0.5014 g of the hydrocarbon component of biological origin was weighed,and base oil component of the Group III was added in an amount to obtaina total weight of 10.0000 g; for the second sample, 1.0137 g of thehydrocarbon component of biological origin was weighed, and base oilcomponent of the Group III was added in an amount to obtain a totalweight of 10.0232 g. The measured results are summarized in Table 7below. Content of radioactive carbon (¹⁴C isotope) is expressed as“percent modern carbon”, based on the content of radioactive carbon ofthe atmosphere in 1950. At present, the content of radioactive carbon ofthe atmosphere is about 107%. δ¹³C value shows the ratio of stablecarbon isotopes ¹³C/¹²C. By means of this value, the isotopefractionation found in our process may be corrected. Actual results arepresented in the last column.

TABLE 7 Content of radioactive carbon Sample ¹⁴C content, % δ¹³ C Bioproportion, % Mineral oil  0.1 ± 0.07 −29.4 0 Bio oil 106.7 ± 0.4  −28.9100 Mineral + bio, 5% by weight  5.0 ± 0.3  −29.3  4.60 ± 0.28 Mineral +bio, 10% by weight  10.8 ± 0.3  −26.9 10.04 ± 0.29

Example 8 Carbon Number Distribution

The proportion of hydrocarbons in certain carbon number range of thebase oil product is dependent on distillation. In FIG. 3 the carbonnumber distributions of VHVI (413-520° C. cut) and the baseoils ofinvention (360-° C. cut) are shown. The carbon number distribution ofthe base oils according to invention is narrower than that ofconventional base oils when distillation is cut in similar mannerat >413° C. corresponding to C26 paraffin. In addition to the narrowcarbon number distribution, the baseoils of the invention contain alsohigher amount of higher boiling fractions compared to the conventionalproduct of same viscosity range (KV100 about 4 cSt), as shown in FIG. 3.The lower boiling components with carbon number <C31 are due to crackingin isomerization. The higher boiling compounds enhance VI.

1. Process for producing branched hydrocarbons, said process comprisingthe steps wherein a feedstock comprising at least one unsaturatedcompound selected from the group consisting of triglycerides, carboxylicacids having a carbon number C1-C38, esters of C1-C38 carboxylic acidswith C1-C11 alcohols, esters of C1-C38 carboxylic acids with C12-C38alcohols, natural waxes and dicarboxylic acids, is subjected to anisomerization step at a temperature from 150-350° C. and under apressure of 0-5 MPa in the presence of isomerization catalyst, then aketonisation step is carried out in the presence of metal oxide catalystunder a pressure from 0 to 10 MPa and at a temperature ranging from 100to 500° C., and the ketonisation product is hydrodeoxygenated in thepresence of a hydrodeoxygenation catalyst under a hydrogen pressureranging from 0.1 to 20 MPa at a temperature ranging from 100 to 500° C.2. The process according to claim 1, wherein the feedstock comprises atleast one compound selected from the group consisting of C4-C24 fattyacids, C4-C24 fatty acid alkyl esters, esters of C4-C24 fatty acids withC12-C24 fatty alcohols, derived from starting material of biologicalorigin, and mixtures thereof, and monocarboxylic acids and dicarboxylicacids.
 3. The process according to claim 2, wherein said startingmaterial of biological origin is selected from the group consisting ofplant fats, plant oils, plant waxes, animal fats, animal oils, animalwaxes, fish fats, fish oils, fish waxes, starting materials derived fromalgae and insects, and a. free fatty acids or fatty acids obtained byhydrolysis, acid transesterification or pyrolysis reactions from plantfats, plant oils, plant waxes, animal fats, animal oils, animal waxes,fish fats, fish oils, fish waxes, and b. esters obtained bytransesterification from plant fats, plant oils, plant waxes, animalfats, animal oils, animal waxes, fish fats, fish oils, fish waxes, andc. fatty acid alkyl esters obtained by esterification of alcohols withfatty acids of plant, animal and fish origin, and d. waste and recycledfood grade fats and oils, and fats, oils and waxes obtained by geneticengineering, and e. mixtures of said materials.
 4. The process accordingto claim 1, wherein a hydrocarbon or a mixture of hydrocarbons is addedto the feedstock and/or as a diluent to process steps.
 5. The processaccording to claim 1, wherein the isomerization step is carried out at atemperature from 200 to 290° C. and under a pressure of 0.1-2 MPa. 6.The process according to claim 1, wherein the isomerization catalyst isan acidic catalyst.
 7. The process according to claim 1, wherein from 0to 8% by weight of water or alcohol is added to the feedstock.
 8. Theprocess according to claim 1, wherein the ketonisation step is performedunder a pressure from 0.1 to 5 MPa and at a temperature ranging from 100to 400° C.
 9. The process according to claim 1, wherein the metal oxidecatalysts is Na, Mg, K, Ca, Sc, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr,Mo, Rh, Cd, Sn, La, Pb, Bi, or a rare earth metal oxide on the laterite,bauxite, titanium dioxide, silica and/or aluminum oxide support.
 10. Theprocess according to claim 1, wherein the metal oxide catalysts ismolybdenum, manganese, magnesium, iron and/or cadmium oxides on silicaand/or alumina support.
 11. The process according to claim 1, whereinthe metal in the metal oxide is molybdenum, manganese and/or magnesiumwithout support.
 12. The process according to claim 1, wherein saidhydrodeoxygenation is performed under a hydrogen pressure ranging from 1to 15 MPa and at a temperature ranging from 150 to 400° C.
 13. Theprocess according to claim 1, wherein said hydrodeoxygenation catalystcontains at least one component selected from the group consisting ofmetals of the Group VIII or Group VIA of the periodic system of theelements, and a support.
 14. The process according to claim 1, whereinsaid hydrodeoxygenation catalyst contains Pd, Pt, Ni, NiMo or CoMometals, and active carbon, alumina and/or silica supports.
 15. Theprocess according to claim 1, wherein prior to the ketonisation stepprehydrogenation is performed under a hydrogen pressure between 0.1 and20 MPa and at a temperature between to 50 and 400° C., in the presenceof a prehydrogenation catalyst.
 16. The process according to claim 15,wherein the prehydrogenation catalyst contains at least one componentselected from the group consisting of metals of the Group VIII and VIAof the periodic system of the elements, and a support.
 17. The processaccording to claim 15, wherein the prehydrogenation is performed under ahydrogen pressure between 1 and 15 MPa and at a temperature between 100and 300° C.
 18. The process according to claim 15, wherein theprehydrogenation catalyst is a supported Pd, Pt, Ni, Ru, Rh, NiMo orCoMo catalyst, and the support being active carbon, alumina and/orsilica.
 19. The process according to claim 1, wherein following thehydrodeoxygenation step dewaxing is performed.
 20. The process accordingto claim 19, wherein the dewaxing step is hydroisomerization carried outunder a hydrogen pressure ranging from 1 to 15 MPa at a temperatureranging from 200 to 400° C. in the presence of a hydroisomerizationcatalyst.
 21. The process according to claim 20, wherein thehydroisomerization catalyst contains a metal of the Group VIII of theperiodic system of the elements and/or a support.
 22. The processaccording to claim 20, wherein the hydroisomerization catalyst containsa molecular sieve and a Pd, Pt or Ni metal and/or a support, saidsupport being alumina and/or silica.
 23. The process according to claim1, wherein base oil, diesel component or gasoline is produced.